Hi, can you sum up in your own words what was wrong with the previous code and why does your work?

/** @param int[] $input */
function (array $input) {
    $i = 0;
    // $input[$i] is int
    \assert($input[$i] === 1);
    // $input[$i] is 1
    $i++;
    // $input[$i] is 1 (without this PR)
    // $input[$i] is int (with this PR)
};

PHPStan was only extracting the first variable referenced so in the string $input[$i] it would only find $input which is not being assigned so is not unset. My change results in both $input and $i being found, $i is being assigned so the known value of $input[$i] is unset.

Of course, nice find! Thank you.